day 10 solution, helped by reddit

day10/day10.py

@@ -0,0 +1,58 @@
+from time import time
+
+
+def reverse(text, repeat):
+    knot = list(range(256))
+    pos = 0
+    skip = 0
+    for isntevenused in range(repeat):
+         for i in text:
+            temp = []
+            for j in range(i):
+                temp.append(knot[(pos+j) % 256])
+            for j in range(i):
+                knot[(pos+i-1-j) % 256] = temp[j]
+            pos += skip + i
+            skip += 1
+    return knot
+
+
+def dense(knot):
+    dense = [0]*16
+    for i in range(16):
+        dense[i] = knot[16*i]
+        for m in range(1, 16):
+            dense[i] ^= knot[16*i+m]
+    return dense
+
+
+def kh(dense):
+    knothash = ''
+    for i in dense:
+        if len(hex(i)[2:]) == 2:
+            knothash += hex(i)[2:]
+        else:
+            knothash += '0' + hex(i)[2:]
+    return knothash
+
+
+start = time()
+
+inp = '102,255,99,252,200,24,219,57,103,2,226,254,1,0,69,216'
+text = [102,255,99,252,200,24,219,57,103,2,226,254,1,0,69,216]
+text2 = []
+
+for i in range(len(inp)):
+    text2.append(ord(inp[i]))
+text2 += [17, 31, 73, 47, 23]
+
+knot = reverse(text, 1)
+sparce = reverse(text2, 64)
+
+dense = dense(sparce)
+knothash = kh(dense)
+
+print('Part One: ' + str(knot[0]*knot[1]))
+print('Part Two: ' + knothash)
+print('Completed in ' + str(time() - start) + ' seconds.')
+